Interactive Display System With Collaborative Gesture Detection

ABSTRACT

An interactive content delivery system ( 10 ) includes means for displaying visual content ( 20 ) to a group of individuals ( 14 ), means for detecting a collective gesture ( 12 ) of the group, and a control system ( 26 ), coupled to the means for displaying visual content ( 20 ) and the means for detecting a collective gesture ( 12 ). The control system ( 26 ) is configured to modify the content in response to the collective gesture.

BACKGROUND

For digital signage in public places, it is desirable to provideinteresting and attractive display systems that can capture and hold theattention of an audience. Most often, public advertising and displaysare “open looped” and provide no direct feedback regarding theireffectiveness in drawing attention. Instead, content providers andadvertisers provide display content that they believe will appeal to thedesired audience, but can generally only gauge its success indirectly,such as through sales figures, opinion polls, focus groups, etc.Additionally, public display systems generally provide little or no wayfor audience members to interact with the system or with other audiencemembers.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features and aspects of the present disclosure will be apparentfrom the detailed description which follows, taken in conjunction withthe accompanying drawings, which together illustrate, by way of example,features of the present disclosure, and wherein:

FIG. 1 is a semi perspective, semi schematic diagram of one embodimentof an interactive display system with collaborative gesture detection;

FIG. 2 is a diagram of another embodiment of an interactive displaysystem with collaborative gesture detection, showing audience membersgenerally collaborating in a given gesture;

FIG. 3 is a diagram of another embodiment of an interactive displaysystem with collaborative gesture detection, showing audience membersgenerally collaborating in another gesture; and

FIG. 4 is a flow chart showing the steps in one embodiment of a methodfor collaborative gesture detection in an interactive display system.

DETAILED DESCRIPTION

Reference will now be made to exemplary embodiments illustrated in thedrawings, and specific language will be used herein to describe thesame. It will nevertheless be understood that no limitation of the scopeof the present disclosure is thereby intended. Alterations and furthermodifications of the features illustrated herein, and additionalapplications of the principles illustrated herein, which would occur toone skilled in the relevant art and having possession of thisdisclosure, are to be considered within the scope of this disclosure.

For digital signage in public venues, it is important to createcompelling experiences that can repeatedly captivate the attention of anaudience. As noted above, the detection and identification of audienceresponses to a display or advertisement can provide valuable feedbackfor a content provider regarding the quality and appeal of the contentto its audience. Such feedback can also be used to allow dynamicmodification of the display content.

This disclosure presents embodiments of a system and method fordetecting collaborative gestures of an audience using vision-basedtechnologies to enable interactivity for digital signage and otherapplications. In one embodiment, the present system and method detectscollaborative gestures, instead of detecting one single gesture or twoor more competitive or even independent gestures, and uses these asfeedback for an audio-visual display system.

One embodiment of an interactive display system 10 with collaborativegesture detection is shown in FIG. 1. The system includes at least oneimaging device 12 (e.g. a camera) pointed at an audience 14 (located inan audience area 16 that represents at least a portion of the field ofview of the imaging device), and a video camera computer 18,interconnected to the imaging device and configured to run gesturedetection and recognition algorithms. The video camera computer is avideo image analysis computing device that is configured to analyzevisual images taken by the imaging device. The imaging device can beconfigured to take video images (i.e. a series of sequential videoframes that capture motion) at any desired frame rate, or it can takestill images. The term “video camera computer” is used to refer to thecomputing device that is interconnected to the imaging device, and isnot intended to limit the imaging device to a camera per se. A varietyof types of imaging devices can be used. It should also be recognizedthat the term “computer” as used herein is to be understood broadly asreferring to a personal computer, portable computer, content server, anetwork PC, a personal digital assistant (PDA), a cellular telephone orany other computing device that is capable of performing the functionsnecessary for receiving input from and/or providing control or drivingoutput to the various devices associated with the interactive displaysystem.

The imaging device 12 is positioned near a changeable display device 20,such as a CRT, LCD screen, plasma display, LED display, projectiondisplay (front or rear projection) or other type of display device. Fora digital signage application, this display device can be a large sizepublic display, and can be a single display, or multiple individualdisplays that are combined together to provide a single composite imagein a tiled display. This can include one or more projected images thatcan be tiled together or combined or superimposed in various ways tocreate a display. An audio broadcast device, such as an audio speaker22, can also be positioned near the display to broadcast audio contentalong with the video content provided on the display.

The system shown in FIG. 1 also includes a display computer 24 that isinterconnected to provide the desired video and audio output to thedisplay 20 and the audio speaker 22. As shown in FIG. 1, the videocamera computer 18 can be interconnected to the display computer 24,allowing feedback and analysis from the video camera computer to be usedby the display computer. The display computer can also provide feedbackto the video camera computer regarding camera settings to allow thechange of focus, zoom, field of view, and physical orientation of thecamera (e.g. pan, tilt, roll), if the mechanisms to do such areassociated with the camera. The camera computer 18 can include aninput/output device 25, having a keyboard, monitor, and other input andoutput devices (e.g. computer mouse, etc.) for allowing direct input andoutput of data to and from the camera computer. Similarly, the displaycomputer 24 can also include an input/output device 27 for allowingdirect control of the display 20.

It is to be understood that a single computer can be used to controlboth the imaging device 12 and the display 20. Such a configuration isshown in FIG. 3, wherein a single computer 26 is interconnected to boththe imaging device 12 and the display device 20. This single computercan be programmed to handle all functions of video image analysis andcontrol of the imaging device, as well as controlling output to thedisplay. As with the dual computer controller configuration shown inFIG. 1, this single computer controller can also include an input/outputdevice 29 for allowing direct control of and feedback to/from thesystem.

Additionally, the computer controller can be a network or part of anetwork, such as a local area network (LAN), or it can be interconnectedto a network. For example, as shown in FIG. 2, the display computer 24can be interconnected to a network 32, which provides an interconnectionto a remote computer system 34. Alternatively, the combined controllingcomputer 26 shown in FIG. 3 can also be interconnected to the networkand thus to one or more remote computer systems 34. The network 32 canbe a local area network (LAN), or any other type of computer network,including a global web of interconnected computers and computernetworks, such as the Internet. The network connection allows the remotecomputer to receive input from the controller for the interactivedisplay system, and also to provide control commands and other output toit.

The controller can be any type of personal computer, portable computer,or workstation computer that includes a processing unit, a systemmemory, and a system bus that couples the processing unit to the variouscomponents of the computer. The processing unit may include one or moreprocessors, each of which may be in the form of any one of variouscommercially available processors. Generally, each processor receivesinstructions and data from a read-only memory and/or a random accessmemory. The controller can also include a hard drive, a floppy drive,and CD ROM drive that are connected to the system bus by respectiveinterfaces. The hard drive, floppy drive, and CD ROM drive containrespective computer-readable media disks that provide non-volatile orpersistent storage for data, data structures and computer-executableinstructions. Other computer-readable storage devices (e.g., magnetictape drives, flash memory devices, and digital versatile disks) can alsobe used with the controller.

The imaging device 12 is oriented toward an audience 14 of individualpeople 28, who are gathered in the audience area, designated by outline16. While the audience area is shown as a definite outline having aparticular shape, this is only intended to represent that there is somearea near the imaging device 12 in which an audience can be viewed. Theaudience area can be of a variety of shapes, and can comprise theentirety of the field of view of the imaging device, or some portion ofthe field of view. For example, some individuals 30 in FIG. 1 can benear the audience area and perhaps even within the field of view of theimaging device, and yet not be within the audience area that will beanalyzed by the vision recognition system.

In operation, the display 20 (and the audio speaker 22) provides visualand/or audio-visual content to the audience. The content can be in theform of commercial advertisements, entertainment, politicaladvertisements, survey questions, or any other type of content. Thiscontent can include suggestions, requests, or other types of prompts foraudience response in the form of some gesture. These requests or promptsare for group responses. The gesture requested can be a certain motionof the body, including relatively subtle motions, such as a smile,facial gesture or nod of the head, to more obvious gestures, such asraising or waving a hand, or moving the entire body in some way, such asin a dance or exercise movement. It will be apparent that there are manytypes of gestures that can be prompted and recognized.

Examples of certain group gestures that the system can recognize aredepicted in FIGS. 2 and 3. In these examples, prompts for particulargestures are used. However, prompts need not be used, and detectedgestures or behavior can be discerned and appropriate feedback taken. Asone example, in FIG. 2 the group 14 has been prompted to raise a hand inresponse to some query provided by the display system. Whenever thesystem prompts a group response, several results are possible. Most ofthe participants are likely to respond in the manner requested and raiseone hand, these group members being indicated at 28 a. However, someparticipants may provide an alternate, though potentially qualifyingresponse, such as by raising two hands. Such an individual is indicatedat 28 b.

Other audience members may respond with an ambiguous or improperresponse, such as the individual 28 c that is holding both arms outhorizontally. Finally, some audience members may give no response atall, such as the individual 28 d. A visual image of the audienceresponse is taken by the imaging device 12, and is analyzed by the imageanalysis computer 18.

Vision based gesture detection and recognition have been widely studiedin the past decade. Vision-based detection captures an audience's viewvia image-processing techniques such as background subtraction,silhouette detection, etc., in order to detect and classify specificgestures. For example, audience participants positioned near the imagingdevice can collectively perform some type of individual gesture (e.g.raise a hand) in response to the content, or they can perform acollaborative gesture, such as a group dance movement. Alternatively,audience participants can line up in a specified way or work together insome other way.

Using group gesture detection techniques that have been developed, theimage analysis that the system performs can function in at least twobasic ways. One mode of operation of the system is to measure the levelof audience interest as a function of the audience response (e.g.looking for a majority response). For example, the simultaneous raise ofmany hands in the audience can be detected and regarded as a highlypositive feedback to the displayed content. For example, if the promptprovided to the audience in FIG. 2 related to a choice betweenalternatives for subsequent content, and the system were programmed toprovide content based upon a majority vote of the audience, the audiencegestures shown in FIG. 2 would suggest that 12 out of the 15 audiencemembers approved of a particular option that was then being offered. Thedisplayed content can then be adapted or modified based upon thismajority vote to provide content indicated by the audience response, andhopefully further captivate the audience's attention.

A second way that the system can perform is to prompt the involvement ofmany individuals to interact with the display system to escalate thelevel of interactivity. For example, an audience can be prompted tosimultaneously emulate or mimic a specific gesture indicated by thedisplayed content. An example of such interaction is shown in FIG. 3. Inthis figure the audience 14 can be performing a group dance or exercisemotion or routine, mimicking motions that are simultaneously shown onthe display 20. If the routine requires that each audience member bestanding on one particular leg at the moment shown in the figure, it canbe seen that some audience members 28 e are performing the actionproperly, other members 28 f are performing the basic motion in reverse,some audience members 28 g are performing an entirely different motion,and still other members 28 d are not performing at all.

While there is likely to be some variation in audience response, theassumption is that group is acting together to some extent, providing acollaborative response to the displayed content. The terms“collaborative gesture” or “group gesture” or “collective gesture” referto those gestures by multiple individuals that present a sufficientlevel of relationship or similarity, or those following a certain typeof indication provided by the digital signage system, or those fallinginto a predefined gesture candidate class. For example, the audience canbe informed or may know in advance a desired collaborative gesture(s)that will elicit some response, or the system can be configured to allowthe audience to discover such gesture(s).

The collaborative gestures to be detected are not limited to humanhands, but can include the movement of one's head, torso, leg, foot, orother body part, as well as facial expressions. The gestures can alsoinvolve physical motions, or change of bodily orientation, such asturning to the left or to the right, or moving towards or away from thedisplay device. In essence, collaborative gestures refer to thosegestures that the audience has presented as a group behavior, ratherthan as individual behavior. Other examples include detectingsophisticated body movements such as a large number of audience membersperforming jumping jacks or other dance-like movements to trigger and/orcontrol some event(s). One example of this concept is a group dancecompetition or Tai-Chi contest that awards every audience member a“prize” if enough audience members perform (e.g. dance to the beat) wellenough. Additionally, the content of the display can include a promptrequesting competing common group gestures from at least two subgroupsof the group. For example, the display system can prompt a first half ofthe group to perform some dance or exercise motion, then prompt theother half of the group to perform the same motion, and then rate thetwo performances relative to each other. Other variations are alsopossible.

Collaborative gestures can include the same or similar movementperformed by one or more people, and can also include coordinated andcomplementary gestures. For example, rather than every audience memberpointing in a common direction, the audience can be prompted to pointtoward a common location, which provides an image in which the apparentdirection of pointing by each individual varies depending upon thelocation of the individual because of perspective differences. Asanother example of collaborative but varying motion, an audience can beprompted to perform a rising and falling “wave” motion, like thatfrequently done by audiences at sporting events. Collaborative gesturescan provide the mechanism to allow multiple user interactivitysimultaneously.

In this system, the visual analysis system detects the collaborative orcollective gestures to collect the audience response from a large crowd,rather than recognizing distinct gestures of individuals, or merelycompetitive gestures, as are detected for video games and the like.Rather than taking a response from one single individual and leaving therest of the audience (e.g. the majority) passively ignored, in thissystem the entire audience is encouraged to coordinate with each otherthrough collaborative gestures to form a group that interacts with thesystem. The system is designed to respond to the group behavior, insteadof each distinct individual behavior. In this way many individuals in anaudience can interact with the system simultaneously and cooperatively.This system thus provides a new mechanism for a crowd to interact with adigital signage or other content delivery system. The capability forgroup interaction is useful for a digital signage system so that theaudience can become actively involved, potentially increasingadvertising and business opportunities and creating greater audiencedraw and word-of-mouth interest.

In the system and method disclosed herein, because of the manyindividuals present in the audience, a control point can be establishedbased upon a number of individuals who present the promptedcollaborative gesture. That is, instead of setting up many controlpoints, each based upon a single individual at a time, many moreaudience members can get involved in controlling or providing feedbackto the system based upon a single collective control point. For example,hand gestures can be detected and used to manipulate a single controlpoint on the display, in a manner similar to the way in which a computermouse is used to control a cursor. By measuring collaborative behavior,this approach allows multiple users to manipulate the control pointsimultaneously, rather than one control point per individual, withoutcausing conflicts. The control point can be triggered by thecollaborative gestures of multiple individuals. In this case, thecollaborative gestures can be hand gestures that can concurrently followsimilar motion patterns detected in the audience.

The steps involved in one embodiment of the interactive content deliverysystem with collaborative gesture detection are outlined in FIG. 4. Tostart the process, the System first provides some initial display output(step 50). As noted above, this content can be in the form of commercialadvertisements, entertainment, political advertisements, surveyquestions, or any other type of content. This content can include overtsuggestions, requests, or other types of prompts for audience responsein the form of some gesture. On the other hand, the content can alsoinclude covert or subconscious prompts or triggers for response. In thefirst case, the content expressly instructs or requests the audience tomake a particular gesture. In the latter case, the content can becrafted so that particular gestures, such as a smile, are likely (e.g.by presenting humorous content), but the content does not expresslyinstruct the audience to make the gesture. In other examples, thecontent can comprise no prompts, explicit or covert, and simplycategorize the detected gestures against one or more pre-determinedpatterns of gesture/behavior. This can be useful for validatingexpectations of reactions against actual reactions.

Once some display output is provided, the system then captures anaudience view with the imaging device(s) (step 52). This step caninvolve capturing a single snapshot or a series of frames/video. It caninvolve capturing a view of the entire camera field of view, or only aportion of the field of view (e.g. a region, only black/white vs color,etc). Additionally, it is to be understood that multiple imaging devicescan be used simultaneously to capture video images for processing.

The next step is to detect the group gesture or behavior (step 54). Forexample, this can be done by detecting multiple individual gestures.This is the first part of the image processing step. Using visionrecognition systems that have been discussed above, the system candetect one or more pre-determined patterns of gesture/behavior. Thegesture or behavior that is detected can be a facial expression, amotion, or some other type of gesture. It should also be noted that itcan be desirable to pre-calibrate the imaging device(s) to simplify theimage processing step. For example, a multi-camera embodiment can beused in conjunction with techniques known in computer vision to solvefor the epipolar geometry between cameras and reduce motion estimationdown to a simpler 1-D search. Other types of pre-calibration procedurescan also be performed.

A variety of computer vision and image processing techniques may beperformed either sequentially or in parallel to analyze the capturedimage data. For example, low-level detection algorithms such asforeground/silhouette extraction and background subtraction may first beformed to identify the sufficiently large and moving contiguous regionsin the scene. The algorithms then proceed to track over time and adjustthese regions to conform with the captured data. Other detectionalgorithms may be present to help identify simpler gestures/behaviorsthat together form a much more sophisticated one. These might includedetectors for face, expression (e.g. smile, frown), body part (head,hand, torso, arm, leg, foot, etc). The system can then detect thegesture or behavior based on one or more of these simpler detectors. Forexample, a jumping jack motion could be broken down into a range ofexpected motions for two arms and two legs, as well as a torso thatmoves up and down.

Alternatively, the system can be configured not to require sophisticatedgesture recognition algorithms at all. Instead, the vision-based systemcan be configured to identify whether there is a correlation betweenmultiple gestures that have been present between multiple people. Thecollaborative gesture may include simultaneous gestures or symmetricgestures, for example. The non-rigidity of the human body and thevariety of appearance affects the accuracy and effectiveness of gesturerecognition. Consequently, there is often a trade-off between simplicityof the recognition program and its accuracy. One way to approach thistrade-off is to create a predefined set of collaborative gestures to berecognized from an audience, with vision characteristics of these storedin memory in the system controller, thereby reducing the level ofcomplexity of the vision recognition system.

The next step in the method is to recognize the collaborative behavior(step 56). This step can include aggregating or correlating the resultsor detecting similarity in gestures to recognize collaborativegestures/behaviors. In this step the system analyzes the input data andcomputes scores based on various detectors to rank the probability ofthe appearance of one or more collaborative gestures/behaviors. Thereare many examples of such collaborative gestures. One type ofcollaborative gesture can be the raising of hands in the audience, anddetecting this gesture using gesture recognition technologies. This caninclude the raise of one hand or two hands to deliver feedback from theaudience regarding the displayed content, or a finger pointing gestureperformed by multiple people at the same time. This scenario can besimilar to the “majority vote” approach, in which the number of raisedhands is counted and considered as the voting behavior. It is to beunderstood that raised hands are just one of many collaborative gesturesthat can be considered. For example, the detection of raised hands couldbe considered together with the detection of facial expression andmotion detection to obtain a more precise measurement of an audienceresponse to the displayed content. Moreover, the system can beconfigured to not merely tabulate a simple majority vote. For example,the system can be configured to compute a score or rating, such as ascore on a scale of from 0-10, as a rating or measure of the relativequality of the gesture. For example, the score can indicate the strengthof positive (or negative) feedback from the audience. Alternatively, thescore can be a qualitative judgment of the collaborative behavioritself, such as a rating of a dance or exercise performance or someother competitive activity.

Many other types of gestures can also be aggregated or correlated. Forexample, facial expressions can be detected to focus on, for example,smiling faces in the audience. The system can focus on all smiling facesas a collaborative gesture at some specific instant. The number ofsmiling faces, the duration of each smiling face, as well as the extentof the smile can be detected using face vision technologies, and theresults can then be aggregated to make a decision. This type ofcollaborative gesture can be used to provide feedback regarding thecontent on the display (e.g. to evaluate the quality of the content thattriggered the smile in the audience), or it can be used as a controlmechanism to allow modification or adaptation of the content, asdiscussed more below.

Object detection and tracking techniques can also be used to detect andtrack motion trajectories for each individual in a crowd. After anindividual motion has been detected, the analysis can focus on thedirection and velocity of the motion across all the motion trajectories.For example, the collaborative gesture can refer to motions that followa common or similar trajectory, direction and/or velocity. The systemcan also be configured to adapt content based on the number of motiontrajectories that follow a particular velocity, direction or trajectoryof motion.

Based upon the recognized behavior, the system can take any of severalactions. In one embodiment, the system can modify the display outputbased upon the collective behavior (step 58). This can involvetriggering one or more outputs from the display computer (24 in FIG. 1)based on the detected gesture. To form an interactive system, an inputfrom the audience usually translates into some sort of output. Forexample, through the detection of collaborative gestures, a digitaldisplay might be updated and/or controlled. Collaborative gestures arepossible to be presented by a crowd in the audience if a certain type ofindication is provided by the displayed content for the audience toeasily repeat and mimic. The response has to be implemented by a groupof people rather than one single distinct individual. Advantageously,the displayed content can guide the audience in an intuitive way toperform the collaborative gestures. The system may count the number ofindividuals that are in the audience whoever follows the designatedgesture, and the content can be adapted by the number of suchindividuals. In this and other ways the collaborative gesture canoperate as a selecting action for alternative content.

In addition to or as an alternative to modifying the display content,the collaborative behavior can be evaluated as feedback regarding thecontent or effectiveness of the display content. This allows the systemto provide a direct indication of the effectiveness or impact ofadvertising, entertainment, political messages, etc. Again, the feedbackcan be in the form of a simple yes/no indication, or it can be a morerelative measure of effectiveness, such as an impact score as adistribution or percentage (e.g. 14% very positive reaction, 20%positive reaction, 23% negative reaction, 15% very negative, 28% nodiscernable reaction).

At this point the process can repeat itself. The modified displaycontent can include a prompt for collaborative action on the part of theaudience. In that case, the system again captures an audience view (step52) and analyzes that view to determine what subsequent change to makein the display content. This process can repeat as many times as desireduntil there are no more collaborative gestures to detect (step 60).Nevertheless, the process can be started over again at any time.

The present disclosure thus presents embodiments of a system and amethod for visually detecting group gestures in connection with adigital signage system or other content delivery system, to enable groupinteraction. The system can collect a response from an audience (e.g. amajority response, or multiple simultaneous collaborative gestures) todisplayed content and measure the level of audience interest. Thedisplayed content can then be adapted to further captivate audienceattention. Alternatively, many individuals can interact with the displaysystem to increase the level of interactivity, such as having anaudience simultaneously mimic or emulate a specific gesture indicated bythe displayed content. A control point can be established by the numberof individuals who present the collaborative gesture, instead of settingup the control point by a single individual at a time. Hence many moreaudience members can get involved in controlling the system or providingfeedback.

Embodiments of the present invention can be used for motivatingcoordinated action by the audience. For example, the display caninstruct and guide the audience to mimic a certain action. In thiscontext, collaborative gestures can be viewed as a type of signlanguage. The gestures indicate a special event motivated by theaudience to collaborate with each other. Collaborative gesture involvesthe intentional collaboration or cooperation between two or more people.As an example, the display content can include instructions to performor a demonstration of a certain movement, and the audience can simplyimitate what has been demonstrated or do what has been instructed. Therecan also be some content to create which involves the collaborativegesture to implement the task that has been designated by the content.For example, the audience can be prompted to move a virtual object shownon the display in a manner that requires more than two hands to completethe task. Embodiments of the present invention can also be used toprompt, detect, and evaluate collaborative gestures from multipleaudiences in different locations. For example, multiple interactivedisplay systems with collaborative gesture detection can be provided atdifferent geographical locations and interconnected in a network. Withthis type of system, the collaborative gestures or actions of audiencesat different locations can be combined or analyzed together.

The present invention has numerous advantages. It leverages novelcollaborative gesture detection as a new interactivity mechanism fordigital signage applications to create a compelling experience for theaudience. The proposed interactivity mechanism is deliberately designedto take the response from multiple users in collaboration and/orcoordination and rewards the involvement of multiple users. For example,in one embodiment the system detects gestures from multiple individualsregardless of their appearance (e.g. height, weight, shape, apparel,etc) and identifies the relationship (e.g. similarities) among thesegestures present from different individuals. The system counts thenumber of users that present the collaborative gestures and thendelivers an appropriate response based on the number of users (e.g. thecontent could be updated as a result of the coordination of manyindividuals). In the end, it attempts to capture more of the audience'sattention and enables group behavior interactivity between the signagesystem and the large crowd of users.

In addition, system embodiments can be less complex and thus requireless sophisticated hardware to implement than other visual recognitionor gesture detection systems. Typical gesture recognition is acomplicated task that involves motion detection, motion modeling, motionanalysis, pattern recognition, and machine learning, whereascollaborative gesture detection can be a much easier task to implement.The detection of collaborative gestures does not need to explicitlyrecognize human gestures. Rather, it needs only to detect whether thereexists two or more gestures that are related to each other, thereforesimplifying the technical challenges.

While the above discussion has focused primarily on digital signageapplications, the ideas of collaborative gesture detection can also beextended to other applications not requiring a large display. Forexample, collaborative gesture detection can be used to evaluate,measure, or judge a collaborative activity or performance, such as asynchronized swimming routine. Other types of group gestures, motions oractivities can also be analyzed through the detection of collaborativegestures.

It is to be understood that the above-referenced arrangements areillustrative of the application of the principles disclosed herein. Itwill be apparent to those of ordinary skill in the art that numerousmodifications can be made without departing from the principles andconcepts of this disclosure, as set forth in the claims.

1. An interactive content delivery system (10), comprising: a displaydevice (20), suitable for displaying content to a group (14) ofindividuals; a collective gesture detection device (12), configured todetect and analyze a collective gesture of the group (14); and a controlsystem (26), coupled to the display device (20) and the group gesturedetection device (12), configured to modify the content in response tothe collective gesture.
 2. An interactive content delivery system inaccordance with claim 1, wherein the display device (20) is a videodisplay device.
 3. An interactive content delivery system in accordancewith claim 2, further comprising an audio broadcast device (22),synchronized with the video display device (20).
 4. An interactivecontent delivery system in accordance with claim 1, wherein thecollective gesture detection device (12) comprises: an imaging device(12); and an image analysis computer system (18) coupled to the imagingdevice, configured to analyze collective gestures.
 5. An interactivecontent delivery system in accordance with claim 4, wherein the imageanalysis computer system (18) is configured to compute a scoreindicating a relative quality of the collective gestures.
 6. Aninteractive content delivery system in accordance with claim 1, whereinthe control system (26) is interconnected to a remote computer system(34) via a communications network (32), whereby the remote computersystem can provide input to the control system and receive feedbacktherefrom.
 7. An interactive content delivery system in accordance withclaim 1, wherein the content of the display (20) includes a prompt for acommon group gesture.
 8. An interactive content delivery system inaccordance with claim 7, wherein the common group gesture comprises aselecting action for alternative display content.
 9. An interactivecontent delivery system in accordance with claim 1, wherein the contentof the display (20) includes a prompt requesting competing common groupgestures from at least two subgroups of the group (14).
 10. Aninteractive content delivery system in accordance with claim 1, whereinthe modified content includes a characterization of the group gesture.